Create TetherService, a TetherAllowed pref, and use DependencyManager for RegisterProfilePrefs call…

chrome/browser/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 3552 matching lines @@
       "task_manager/sampling/task_group_sampler.cc",
       "task_manager/sampling/task_group_sampler.h",
       "task_manager/sampling/task_manager_impl.cc",
       "task_manager/sampling/task_manager_impl.h",
       "task_manager/sampling/task_manager_io_thread_helper.cc",
       "task_manager/sampling/task_manager_io_thread_helper.h",
       "task_manager/task_manager_interface.cc",
       "task_manager/task_manager_interface.h",
       "task_manager/task_manager_observer.cc",
       "task_manager/task_manager_observer.h",
+      "tether/tether_service.cc",
+      "tether/tether_service.h",
+      "tether/tether_service_factory.cc",
+      "tether/tether_service_factory.h",
       "themes/browser_theme_pack.cc",
       "themes/browser_theme_pack.h",
       "themes/custom_theme_supplier.cc",
       "themes/custom_theme_supplier.h",
       "themes/theme_properties.cc",
       "themes/theme_service.cc",
       "themes/theme_service.h",
       "themes/theme_service_factory.cc",
       "themes/theme_service_factory.h",
       "themes/theme_service_mac.mm",
@@ skipping 1102 matching lines @@
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }
 
 service_manifest("preferences_forwarder_manifest") {
   name = "preferences_forwarder"
   source = "prefs/forwarder_manifest.json"
 }